Traffic solutions?

The RACV says the problems highlight the need for a new arterial road as well as a rail tunnel under the city.

The motoring group's Brian Negus says a tunnel should be built under the city from South Kensington to South Yarra.

Mr Negus says an east-west road tunnel is also badly needed and the State and Federal Governments must commit to long-term investments.

"The east-west tunnel, from Eastern Freeway, across to CityLink, to Tullamarine Freeway and then extended out to the Western Ring Road to both relieve that northern part of Melbourne, but also to provide that alternative route across town," he said.

"And we need the new Metro rail tunnel to provide alternatives for ramped-up public transport services."

Melbourne's traffic gridlock coincided with a transport conference in the city.

As Transurban, the Government and motorists were trying to make sense of the chaos, experts at the conference predicted that the congestion in Melbourne was going to become the norm.

Academics and businesses called for urgent action to head-off what they say is an emerging transport crisis.

"Costs of congestion are about $3 billion a year to the economy," said Monash University's Professor Graham Currie.

"It's going to double by 2020, so people in Melbourne need to get used the fact that our roads are going to get more and more clogged."

Tim Piper from the Australian Industry Group says population growth and a lack of infrastructure are to blame.

A Competition and Efficiency Commission report to the State Government shows that on current projections, congestion will worsen over the next decade.

It predicts most of the increase will be in the north, west and south-east suburbs.

The Australian Industry Group says there should be a big investment in ports and rail to help ease traffic congestion.